Temperature dependence of the electromagnetic and microwave absorption properties of polyimide/Ti₃SiC₂ composites in the X band

Ti₃SiC₂ particles with an average diameter of 5 μm are added into a polyimide matrix to fabricate electromagnetic microwave absorbing materials. The complex permittivity of the composites increases with the increasing Ti₃SiC₂ content due to an enhanced interface polarization and conduction loss. The maximum reflection loss value of the polyimide/Ti₃SiC₂ composite is up to -48.6 dB at 8.5 GHz with a thickness of 2.9 mm and the absorption bandwidth below -10 dB is 3.8 GHz. The complex permittivity shows a remarkable temperature dependent effect in the 8.2-12.4 GHz range, and when the temperature is 400 °C, the bandwidth below -10 dB is 2.48 GHz with an optimum thickness of 2.0 mm. The excellent absorption properties of the polyimide/Ti₃SiC₂ composite mean that it can be used as an attractive candidate for a new type of microwave absorption material at elevated temperature.